The invention relates to an electrode for a glass melting furnace, which comprises a metal electrode shaft to be introduced from outside of and, preferably, above the glass melting furnace into the interior thereof, and of an electrode body of refractory metal such as molybdenum, platinum, tungsten or their alloys, which is joined, e.g., screwed, to the furnace-interior end of the shaft, and is to be mostly immersed in the molten glass in the glass melting furnace, the electrode shaft being of hollow construction and cooled by means of a liquid coolant, and being connectable to an electrical power source.
An electrode of this general kind is disclosed in DE No. 32 07 250 A1. Not only the electrode body but also the electrode shaft consists of refractory molybdenum, platinum or tungsten or their alloys, which results in high material and manufacturing costs and hence high glass furnace operating costs. Moreover, on account of the brittleness of the material used, the shaft has a limited mechanical strength, which has to be compensated by weight-increasing thicknesses. Furthermore, in this known electrode the electrode body is a short cylinder of relatively great diameter. This gives the electrode body good mechanical stability, but as a result the current is fed into the glass melt substantially at a point. This highly localized application of the current results in an irregular energy input and temperature distribution in the glass melt, which is detrimental to the melting process.
Further, elongated plate-like as well as elongated cylindrical electrode bodies are generally known in the glassmaking art. They provide for a regular input of energy to the melt and thus for a better temperature distribution within the melt, but the stability and useful life of these electrode bodies is not always satisfactory; especially when they are used in aggressive melts, great erosion in parts of the electrode body can take place after only a short period of use and consequently the electrode bodies can break off.
It is an object of the invention, therefore to provide an electrode of the kind described above, which will not only be less expensive to make but also have better working qualities.